Mr Rogers NEVER made a claim reference Christians committing mortal sins getting a free ride on such sins. He pointed out in one post the entirety of Romans 8 where Paul tells the Roman church "whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified." Sounds like a promise.
I thought it was clear that he claimed once justified a person could not be condemned no matter what that person did afterward. Do you hold differntly, like the Catholics/Orthodox ?
Quite a loaded question, no? That would be akin to me asking if every Catholic was sincere when confessing their sins to a priest and properly conducting their penance in the pew afterwards. Or asking you if a Catholic is truly absolved of their sins if they sin Monday to Friday knowing they get a clean slate Saturday afternoon in the confessional. Now if I were to suggest such, I would be completely misunderstanding the spirit of Catholic penance, right? I would be portraying a most cynical opinion.
I mean what Catholic in their right mind properly catechised would think they can sin all week and be good to go after kneeling and saying "bless me father for I have sinned..."
You would put such a person out of your church after personally confronting, then with 2 or more witnesses and then if that did not work the entire church. Right?
So...to answer your specific question which Mr Rogers answered several times with Romans 8:
"There is therefore now no condemnation to those who are in Christ Jesus, who do not walk according to the flesh, but according to the Spirit. 2 For the law of the Spirit of life in Christ Jesus has made me free from the law of sin and death."(Romans 8)
If one is walking according to the flesh they don't belong to Jesus. I already posted the references from 1 Thessalonians 4.